of the Goniatite Limestone at Rockford, Indiana. 175 
Lower beds, composed of brownish-buff colored argillaceous 
ng 
ta, Cardiopsis radiata, Productus semireticulatus? Cyr- 
toceras and Gomphoceras (undt. sp.) Nautilus digonus, a 
- - 60 
discoid Goniatite, and a Proetus (undt.) feet. 
3,—Black slate shading upwards to greenish shale, - - 40 
4—Hamilton group, consisting of dark limestone, - - 5 ee 
5.—Niagara group limestone of buff col. - - - 7 A 
Of the fossils mentioned in the above section the following are 
_ usually characteristic of the Chouteau series :— Cyathoxina (undt.), 
Poteriocrinus Meekianus.* Spirifera peculiaris, Athyris Prouti, A. 
Hannibalensis, Chonetes ornata, Cardiopsis radiatus, Nautiius digo- 
nus, and an undetermined Goniatite. Those usually regarde 
strictly Carboniferous are,—Spirifera Grimesi, Orthis Michilini, 
oductus semireticulatus, and Platycerus equilatera. 
The forms common to Carboniferous and Devonian rocks, are 
Strophomena rhomboidalis, and Orthis resupinata. The species 
here enumerated, however, are only those collected at the local- 
ity where this section was taken. Several other Carboniferous 
4 an interesting and important paper on the rocks and fossils 
y Sha occurring in the Burlington limestone, fifteen commenced 
their existence in the beds below, referred .by Prof. Hall to the 
Chemung; which as is well known, represents the Choutean 
limestone of Prof. Swallow. | 
Then we thus find these beds so intimately connected by the © 
general affinities of their organic remains, as well as by the actual 
Mingling of species with the undoubted Carboniferous rocks 
above, and bear in mind that the Chains eae in 
* : . is crinoid, its exact ical position 
‘aie ond inte Dr, beter described this crinoid, i t the tase of a DIA com 
in part of the Choutean beds, and partly urlington limeste 
© position has since been determined to be in vai Pa though it 
Probably also ranges up into the Bur 
